The present invention is directed to a device for controlling ignition circuits for restraining devices.
Firing controls which are designed to work on integrated circuits (IC) are supplemented with additional external hardware for switching off individual igniter groups, such as the igniter dedicated to the front-seat passenger. An example of such additional hardware is MOSFET switches, which are then logically linked with one another.
The device according to the present invention for controlling firing circuits for restraining devices has the advantage that no additional external hardware is necessary; rather, the freely programmable blocking of groups of igniters is possible by the use of internal components of the firing circuit control.
It is especially advantageous that the processor can read out the blocking registers in order to conduct an error analysis of these components of the firing circuit control.
It is further of advantage that, after setting the blocking register, the processor blocks the blocking register to further changes during operation, so that a possibly defective processor has no influence by the arbitrary setting of the blocking register to the activation and blocking of the igniters, that is, the firing circuits.
In addition, it is of advantage that the processor checks the blocking inputs, the blocking register and the logical linkages when the device according to the present invention is switched on. This ensures that the group-wise blocking of igniters is properly carried out. The blocking inputs are checked by the processor via the safety (reliability) IC.
Lastly, it is also of advantage that the firing circuit control has blocking inputs for blocking the plus and minus output stages, so that, thus, all output stages can be blocked.